Santiago, Chile — It was just after midnight. Gerardo Maturana, an announcer for Radio Agricultura, was reading his last news items before the station went off the air.
Suddenly, the newscast was interrupted by an explosion - a bomb had exploded at the front door of the radio station. The windows of the station's three-story building, as well as its door, were seriously damaged. So were several automobiles parked nearby.
The person suspected of having placed the bomb was killed as the explosive went off - apparently before he intended.
The explosion at the station early Thursday was one more incident of violence in a growing wave of protest against the government of Gen. Augusto Pinochet Ugarte and his supporters.
Radio Agricultura is regarded in some quarters as a firm backer of the President. It had broadcast an ''antiprotest'' program a week before the bomb blast.
The Pinochet government dismisses incidents like that at the radio station as the work of a small band of ''delinquents.''
Others are not so sure. Over the past 10 days, there have been 76 violent incidents or protests that resulted in skirmishes between demonstrators and police in the Santiago metropolitan area, according to sources in the carabineros, Chile's national police.
There can be no doubt that the government, no matter what it says about the incidents, is worried. It has beefed up police patrols and rounded up perhaps 50 suspected terrorists.
Actually, the government expected protest as it celebrated the 10th anniversary of its seizure of power in 1973. But the size and scope of the protest of that Sept. 11 anniversary has surprised many.
The government's official announcements shrug off the violence. Some in the government place some of the blame for the level of protest on the presence here of 200-plus foreign correspondents. Foreign Minister Walters Miguel Alex Schweitzer suggested as much in an interview only hours before the bomb blast at Radio Agricultura.
''The small minority of terrorists,'' he said, ''are trying to give Chile a bad image in the world,'' and using the presence of the foreign reporters ''for that purpose.''
Others in the government make the same complaint.
But leaders of the Alianza Democratica, an umbrella group of six opposition political parties, say the protest is legitimate and that Chileans have many grievances.
''It (the demonstrations) represents the frustrations of a people tired of the years of dictatorship,'' says Andres Zaldivar Larrain, a leader in the Christian Democratic Party, which before military rule was Chile's largest political party.
''Christian Democracy does not sanction violence,'' says Mr. Zaldivar, who is president of the International Organization of Christian Democratic Parties. ''But we can certainly understand a people's frustration.''
Like others in the alliance, he warns the government that now is the moment to make headway in finding a way to bring military rule to a conclusion and to restore government to civilian hands.
Some protest leaders, many of whom do not wish to be named for fear of retribution, argue that dialogue between the alliance and the government will lead nowhere.
''This is a trick of the government to fool the people into believing there can be an end to military rule,'' one says, ''but we won't be fooled.''
Some of the protest may indeed be a demonstration of anger over the military's 10-year rule. But many sources, including bishops of the Roman Catholic Church, say the nation's growing economic crisis and its effect on the population is perhaps an even bigger factor.
''Hunger is no longer a minor issue,'' says one bishop. ''Thousands of Chileans are hungry. Unemployment is higher, perhaps twice as high as the government (which says 15.6 percent) admits. At least half of Chile lives on the margins of society. And these are increasingly desperate people.''
Some churchmen accuse the carabineros of excessive violence against protestors, as well. Members of the alliance agree. The head of the carabineros, Gen. Cesar Mendoza Duran, denies the charges.